1. Field of the Invention
This invention pertains to building construction, and more particularly to apparatus used to install electrical wiring in buildings.
2. Description of the Prior Art
Electrical systems are a major part of modern buildings. Even relatively modest buildings have long lengths of electrical wire and numerous outlets for interfacing with switches, plugs, and other devices.
Important components of a building electrical system are electrical boxes. Electrical boxes are available in a wide variety of sizes, shapes, and styles. They serve several purposes such as holding switches, light fixtures, and other devices in place. They protect the junctions of wires with other wires and with various electrical devices. At the same time, they provide access to the wire junctions.
In a building with frame construction, electrical boxes are usually nailed to a stud or rafter to hold the box in place. After the box has been wired, rolls or batts of insulation are usually installed between the studs and rafters. Then the studs and/or rafters and insulation are covered with decorative panels, gypsum board, or other materials. The fronts of the boxes are closed with plates of different kinds to suit the components in the boxes as well as the decorative scheme of the finished walls.
With the ever rising costs of energy, conventional frame building construction is being re-evaluated. To obtain increased insulative value, wider studs are used in external walls to accommodate thicker insulation rolls and batts. However, there is a practical limit for stud width due to the additional expense associated with the studs and their installation.
As an alternative to frame construction with roll or batt insulation for building walls, walls made of expanded polystyrene foam are becoming increasing popular. That foam material has greater thermal resistance than traditional spun fiberglass insulation. The foam is normally supplied as large but light weight panels with interconnecting cutouts. After the foam panels have been erected, concrete is poured into the cutouts to provide structural rigidity to the wall.
Despite their superior insulation characteristics, the use of foam panels in buildings creates a problem in relation to the building electrical wiring. Specifically, the electrical boxes cannot be nailed to non-existent studs. Merely forming a recess in a foam panel for a box is not satisfactory, because the box is not anchored and is prone to falling out of a foam panel.
As one solution to the problem of installing electrical boxes in foam walls, the Wind Lock company of Leesport, Pa., has designed boxes that are surrounded by the concrete poured into the foam panel cutouts. However, those boxes were undesirably expensive. Moreover, since they were embedded in the concrete wall, they could not be easily removed if changes to them were desirable at a later date.
Thus, a need exists for improvements in electrical boxes for foam building walls.